The objectives of this research program are to study the sequence of cellular and molecular events initiated by antigen receptor perturbation and which culminate in T cell activation. These objectives will be accomplished by the techniques of differential nucleic acid hybridization in order to isolate genes that are transcriptionally active as a result of antigen receptor-induced activation. The development of cDNA probes from these genes will allow detailed analysis of T cell activation kinetics and stimulus-response coupling in this critical immunoregulatory cell as well as the identification of previously uncharacterized lymphokines. Aberrant and inappropriate T cell activation has a central role in the etiology of a variety of autoimmune, neoplastic, and hematologic disorders. Delineation of the mechanisms and consequences of immune T cell recognition of antigen will permit the development of novel strategies for specific immunotherapy based on a more complete understanding of the T cell activation sequence.